Recently, the propagation and demand for audio/video oriented multimedia contents are rapidly expanding in various fields of Internet, personal media and the like as well as in fields of broadcasts and movies owing to the developments of the digital technology and the communication technology. As 3D TVs/movies providing 3D effect through broadcasts/movies are generalized, consumer's demands for Immersive Media providing reality and realism are increasing. Moreover, as a TV is equipped with a wide screen at home in addition to the development of a display technology, contents of high image quality amounting to HD or higher are increasingly enjoyed and consumed. To prepare for Post-HDTV markets, Realistic Broadcasting such as 3D TV or UHD (ultra high definition) TV is spotlighted as a next generation broadcasting service. Particularly, the ongoing discussions of UHD (ultra high definition) broadcasting service are increasingly rising.
The goal of UHD broadcasting is to provide viewers with abundant colors, improved image quality and immersion in various aspects in comparison with the existing HD broadcasting. To this end, it is able use a method of extending a range of luminance represented in a content to a dynamic range actually recognizable in human vision system. In particular, by providing improved brightness and high contrast through a ultrahigh definition content, a user currently watching the ultrahigh definition content can experience more immersion and realism. However, a high dynamic range represented in a content is not supported by a display, it may cause a problem that a viewer watches a quality degraded image or an information lost image against content producer's intention.
UHD broadcasting represents brightness failing to be represented in an existing content, thereby being differentiated from the existing broadcasting. The UHD broadcasting can provide a viewer with a high level of realism. Recently, HDR contents tend to be produced through image input equipments having High Dynamic Range (HDR). However, since a display supportive of HDR is still in a stage of prototype development, it causes a problem in fully representing HDR contents. Hence, viewers still experience inconvenience in watching HDR contents.
The UHD broadcasting extends a luminance represented range among various factors for providing a high quality image, thereby providing an image with sense of high reality. To this end, a content should be acquired and produced through equipments capable of accommodating a dynamic range beyond an existing dynamic range and a display or a screening equipment capable of supporting a luminance representation range of such a content should be provided. Yet, in an environment that a display having various luminance related characteristics exists, it may happen that a viewer watches a provided content through a display incapable of sufficiently accommodating a dynamic range of the provided content. Since information for preparing for a display environment of a receiving side is not provided as well as luminance information of a transmitted content in a content providing environment through a current broadcast or digital media, it causes a problem that image quality degradation is generated from the receiving side.